This invention relates to computing devices and more particularly to an apparatus and method of strengthening and protecting the housing for a portable electronic device.
The first personal computers were introduced to the work place, in substantial numbers, in the early 1980""s. Since then, the popularity of computers in the workplace has grown tremendously. Today, computers are commonplace in most work environments and are essential to many daily business transactions.
The first computers introduced to the workplace were stationary and primarily designed to sit on a platform, such as a desk or table. However, as new low-power electronic circuitry such as complementary metal oxide semiconductor (CMOS) was developed alongside new longer lasting batteries (nickel hydride), portable computers began to emerge. Portable computers were attractive to many industries because employees were less confined to their offices. Work could be completed at home or on business trips away from the office.
Portable computers can be classified as being either (a) handheld (palmtop), (b) luggable or (c) laptop (notebook) computers. Palmtop computers are generally characterized by their size and computing capability, which is typically less than a desktop or laptop computer. An example of a palmtop computer is an HP 300LX. Luggable computers are, in essence, desktop computers that are portable. These computers are generally constructed with a handle or handgrip by which the luggable computer may be carried. An example of a luggable computer is an Apple iMac(trademark). Notebook computers are generally characterized by their size and weight as well but their computing capability may equal or exceed that of a luggable or desktop computer. An example of a laptop computer is a Hewlett-Packard OmniBook 900(trademark).
Modern laptop computers are much thinner than their predecessors. The outer surface or housing is typically composed of molded plastic. A display unit (an upper portion of the housing) is attached to a base unit (lower portion of the housing). The lower portion of the housing contains most of the electronic circuitry (henceforth referred to as electronics) and is attached to the upper portion of the housing with a hinge. The housing surrounding the display is typically constructed of molded plastic and consequently is susceptible to bending and twisting which could damage the enclosed electronics. Additionally, if the computer is dropped, the housing does not provide enough protection to prevent damage to the internal electronics. Some computer manufacturers have addressed this problem by constructing selected portions of the housing, specifically the upper portion that supports the screen, of metal. A preferred metal used to construct the upper portion of the laptop housing is magnesium.
Magnesium is a metal that is silvery white in color and is extremely light in weight. Magnesium is approximately two-thirds the density of aluminum and can be combined with other metals to create alloys that are extremely strong. In this regard, magnesium is well suited as a structural material for use in laptop computers. Additionally, magnesium is not very reactive; for example, magnesium reacts only slightly with most organic chemicals including hydrocarbons, aldehydes, alcohols and most oils. Thus, as an outer surface material (housing) for a laptop computer, magnesium is essentially stain resistant.
Manufacturers of conventional laptop computers employing magnesium as a structural material, however, are met with new challenges: (1) molded or die cast magnesium parts, which are commonly used to form the upper surface of the laptop housing, are still lacking in providing adequate support to prevent the upper housing from substantially bending and twisting; (2) magnesium is typically painted when used as a surface material. The painted surface is easily scratched and consequently causes the laptop to appear older thus creating an appearance of being inferior in quality; and (3) magnesium, as a housing material for a laptop computer, is significantly more expensive than molded plastic. Unless one or more of these challenges are addressed, many prospective users of portable electronic devices will conclude that the problems associated with using these devices outweigh their benefits.
A portable electronic device comprises, in one embodiment, one or more risers that protect an upper surface of the housing from being scratched. The risers serve as bumpers to reduce damage to the device if it is dropped or bumped. Another embodiment of the present invention incorporates support members made from metal or metal alloy parts that are selectively attached to the laptop housing. These metal support members provide structural support for the housing and therefore aid in preventing the housing from twisting and bending. To further strengthen the housing, a metal frame is used in the upper and/or lower surface of the housing. The frame also serves to protect the enclosed electronics from electromagnetic interference.